Oxymorphone and its derivatives are conventionally produced by O-demethylation of oxycodone with conventional O-demethylation reagents such as BBr3 and HBr. The yield for these reactions varies, typically from 30% to as high as 80%. Unfortunately, oxycodone is an expensive starting material.
Alternatively, oxymorphone can be produced by oxidation of oripavine, followed by reduction of the intermediate, as illustrated in Scheme 1:

The Scheme 1 method is analogous to the method of making oxycodone from thebaine, which is widely practiced in the industry. The conventional synthesis of oxycodone from thebaine comprises oxidizing thebaine to form 14-hydroxycodeinone followed by catalytic hydrogenation of 14-hydroxycodeinone to form oxycodone. The conventional oxidant is an acid in combination with hydrogen peroxide or another common oxidant.
The use of oripavine is desirable because of its competitive pricing and structural similarity to oxymorphone, compared to thebaine. Unfortunately, the use of oripavine is challenging because oripavine has multiple reactive sites by virtue of attached functional groups. The Scheme 1 reaction yields significant by-products that cannot be easily isolated or removed, resulting in lowered reaction yields. These low yields from oripavine to oxymorphone render this synthetic route impractical on a commercial scale. There is no known reference in the literature to a practical synthesis utilizing oripavine as the starting material for the formation of oxymorphone.
The conventional oxidation processes utilized in opiate synthesis reactions, for example the oxidation of thebaine, typically utilize a peroxyacid, or more specifically peroxyacetic acid, since it is well suited and effective for this reaction. Unfortunately, the use of peroxyacids is dangerous, requiring expensive and time consuming safeguards for preparing, transporting and handling high concentrations of peroxyacetic acid under industrial conditions.
The reduction of 14-hydroxy-6-keto-opiate compounds formed by the oxidation of thebaine or oripavine is typically carried out by catalytic hydrogenation. Although the catalytic hydrogenation for the reduction of an α,β-unsaturated ketone to the corresponding saturated ketone is well known and commonly practiced, expensive pressure reactors are required to contain the potentially explosive hydrogen atmosphere. Therefore, there is a need to provide a simpler, safer synthetic route.